Heel piece

ABSTRACT

A heel holding device for safety ski bindings comprising stationary guide means, pivotal stepping-down means and springloaded pivotal heel holding-down means, said guide means having two surfaces, one being arcuate and substantially parallel the other being flat and substantially vertical with respect to the plane of the ski, said holding-down means being adapted to pivot from said arcuate guide face portion to said vertical guide face portion of the guide means upon said stepping-down means being depressed.

v ll United States atet 11 1 1111 3,776,567 Shimizu et a1. Dec. 4, 1973 54] HEEL PIECE 3,291,500 12/1966 Voster 280/1 1.35 T

3,481,61 12 69 75 Inventors: Giichi Shimizu, No. 3-5-16, NiShl 3 326 x3 Azabu; Teiji Takahashi, both of 3,125,349 3/1964 Schweizer 280/11.35 T

Tokyo, Japan [73] Assignee: said Shimizu, by said Takahashi [22] Filed: Aug. 2, 1971 [21] Appl. No.2 168,109

[30] Foreign Application Priority Data Aug. 5, 1970 Japan 45/67965 [52] US. Cl 280/l1.35 T [51] Int. Cl. A63c 9/00 [58] Field of Search 280/11.35 T

[56] References Cited UNITED STATES PATENTS 3,423,100 l/1969 Huss 280/ll.35 T

Primary ExaminerRobert R. Song Att0rneyOtto John Munz [5 7 ABSTRACT A heel holding device for safety ski bindings comprising stationary guide means, pivotal stepping-down means and spring-loaded pivotal heel holding-down means, said guide means having two surfaces, one being arcuate and substantially parallel the other being flat and substantially vertical with respect to the plane of the ski, said holding-down means being adapted to pivot from said arcuate guide face portion to said vertical glide face portion of the guide means upon said stepping-down means being depressed.

3 Claims, 8 Drawing Figures PATENTEUUEE 419B SHEET 1 M 3 INVENTORS GIICHI SHIMIZU TEIJI TAKAHASHI ATT INrENTORS GI ICHI SHIMIZU TEIJI TAKAHASHI ATIZRNEY PATENTEU same or 3 A MI III.W..\------- a .ski boot and more particularly,

HEEL PIECE BACKGROUND OF THE INVENTION This invention relates to safety ski bindings and more particularly, to heel holding devices for the safety ski bindings.

A great variety of safety ski bindings are known. One typical conventional safety ski binding comprises a toe holding device and a heel holding device. The ski boot is resiliently and bindingly held between the toe and heel holding devices because the heel holding device urges the ski boot forwardly toward the toe holding device. The conventional safety binding also includes a resilient member which is adapted to resiliently absorb a force which urges the ski boot upwardly with respect to the ski by causing the heel holding device to engage the heel of the ski boot if the force is below a predetermined level thereby to return the ski boot to its proper position on the ski, but if the upwardly urging force is over the predetermined level, the resilient member snappingly disengages the heel holding device from the from the ski boot heel. And in the above-mentioned conventional safety ski binding, if the ski boot is subjected to a force which displaces the ski boot laterally with respect to the ski, the toe holding device acts to return the ski boot to the initial position or to push the boot toward the heel holding device. Furthermore, the conventional safety ski binding permits the ski boot to be placed on or taken off the ski in one step motion.

However, in the conventional safety ski binding of the type described above, while the binding is holding the ski boot in position, the heel holding device urges the ski boot toward the toe holding device with a sub stantial force and the two holding device hold and squeeze the ski boot therebetween, Therefore, if the ski boot is subjected to a lateral force which displaces the ski boot with respect to the ski while skiing, since the heel holding device always urges the ski boot forwardly against the toe holding device, the return action of the toe holding device which urges the boot backwardly against the heel holding device will be diminished.

Another type of conventional safety ski binding comprises a toe holding device and a heel holding device including a heel holding-down member. When the skier steps down on a stepping-down member with his ski boot heel, the heel holding-down member initially descends and contacts the upper edge of the heel, and then the skier moves his heel about with its upper edge in frictional contact with the holding-down member until the heel is properly positioned with respect to the heel holding device. Also when the ski boot is released from the binding, the upper edge of the ski boot heel is moved about in frictional contact with the holdingdown member. Therefore, this second-mentioned conventional safety ski binding has the additional disadvantage that since friction occurs between the holdingdown member and the upper edge of the ski boot heel each time the ski boot enters and leaves the binding, the upper edge of the heel is quickly worn out.

Still another type of conventional safety ski binding comprises a toe holding device and a different type of heel holding device. With this binding the resiliency of a resilient member is initially received by a particular member and the thus received resiliency is then transmitted from the particular member through a link or the like member to a stepping-down member or heel holding-down member which holds the heel in position. In other words, the resiliency of the resilient member is indirectly employed for holding the ski boot heel in position and therefore, loss in heel holding force occurs frequently. In addition, such indirect employment of the resiliency or holding-down force inevitably requires a rather complicated mechanism. In order to compensate for the loss in the resilient holding force, the resilient member must be a heavy duty one and it is invariably heavy, large and expensive and does not work smoothly.

SUMMARY OF THE INVENTION Therefore, one object of the present invention is to provide a novel and improved heel holding device for safety ski bindings which can effectively eliminate the above-mentioned disadvantages inherent in the conventional heel holding devices for safety ski bindings described above.

According to the present invention, a ski boot is firmly held in position on the ski between a toe holding device which may be a conventional one and does not constitute any part of the invention and a novel heel holding device which is the subject of the invention as practiced conventionally. The heel holding device of the invention is different from any conventional heel holding device in that the novel heel holding device is not designed to push the ski boot forwardly toward the toe holding device to hold the ski boot against the ski, but applies a substantially vertical holding-down force on the ski boot heel to hold the heel against the ski. Therefore, in a safety ski binding comprising the heel holding device of the invention, even if the ski boot is subjected to lateral stress which tends to displace the ski boot out of its desired or proper holding position on the ski while skiing, the toe holding device can readily return the boot to the proper holding position on the ski because no forwardly directing force is applied to the ski boot.

Also, according to the present invention, when the heel of a ski boot enters the heel holding device, the heel holding-down member operates in a predetermined time delay relationship with the stepping-down member which first operates when the ski boot heel enters the heel holding device; and on the other hand, when the heel is released from the heel holding device, the heel holding-down member operates first, before the stepping-down member operates. When the heel holding-down member engages the ski boot heel, the heel holding-down member applies a substantially vertical holding-down force on the heel so as to press the heel vertically and downwardly against the ski whereby excess wear on the heel which will otherwise inevitably occur because of frictional contact between the heel holding-down member and heel as frequently seen in any of the conventional heel holding devices for safety ski bindings can be effectively eliminated.

Furthermore, according to the present invention, the vertically directed holding-down force of the holdingdown member can be provided directly to the holdingdown member from a vertically disposed resilient member without necessity for any intermediate force transmission means and accordingly, substantially the whole force from the resilient member can be applied to the ski boot heel substantially without any loss in force. The elimination of such an intermediate force transmission means that the entire heel holding device can be made simpler in construction, smaller in size and smoother in operation as compared with the conventional heel holding devices of safety bindings.

Thus, another object of the present invention is to provide a heel holding device for safety ski bindings in which a ski boot is held in position on a ski with a vertically and downwardly directed force from a resilient member. With the present invention the heel of the ski boot is engaged by a heel holding-down member without any friction therebetween and substantially all of the holding-down force provided from the resilient member is utilized only for holding the ski boot against the ski and even if the ski boot is subjected to any stress which tends to force the boot up from the ski, the heel holding-down member effectively holds the heel in contact with the ski.

A further object of the present invention is to provide a heel holding device for safety ski bindings which holds the heel of a ski boot against a ski with the direct holding-down force from a resilient member which acts at substantially right angles with respect to the plane of the ski.

A further object of the present invention is to provide a heel holding device for safety ski bindings in which a heel holding-down member resiliently engages the heel of a ski boot without friction therebetween and bindingly holds the heel against a ski.

A further object of the present invention is to provide a heel holding device for safety ski bindings which is simple in construction and small in size.

A further object of the present invention is to provide a heel holding device for safety ski bindings which is light in weight and convenient in handling.

The present invention provides a heel holding device for safety ski bindings which comprises stationary guide means, stepping-down means pivoted to said guide means and spring-loaded heel holding-down means pivoted to said guide means, said guide means having two guide face portions one of which is normally substantially vertical and the other substantially parallel to the plane of a ski, said spring-loaded heel holding-down being adapted to pivot from said vertical guide face portion to said parallel guide face portion upon pressing down of said stepping-down means.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings which show one preferred embodiment of the invention for illustrative purpose only, but not for limiting the scope of the invention in any way.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of one form of heel holding device for safety ski bindings embodying the present invention;

FIG. 2 is a side elevational view which shows said heel holding device in its ski boot heel holding position;

FIG. 3 is similar to FIG. 2, but shows said heel holding device in its ski boot heel releasing or receiving position; and

FIG. 4 is a vertically sectional view of said heel holding device as shown in FIG. 2.

FIG. 5 is a perspective view of a holding member ac cording to a typical embodiment of the present invention.

FIG. 6 is a perspective view of a stepping-down member according to a typical embodiment of the present invention.

FIG. 7 is a perspective view of a release lever according to a typical embodiment of the present invention.

FIG. 8 is a perspective view showing the structural relationship between a spring case, a stepping-down member and a release lever in a position of rotating the lever to the clockwise direction.

DESCRIPTION OF THE PREFERRED EMBODIMENT The heel holding device for safety ski bindings of the invention comprises a main body which is generally shown by reference numeral 30 (FIGS. 2, 3 and 4). It is fixedly mounted on an attachment plate 1 which is in turn secured to a ski (not shown) by means of screws or the like conventional securing members through holes lb and extends along longitudinally of the ski. The attachment plate 1 is substantially U-shape comprising two parallel lanes la, la and a bridge portion 1c connecting the front parts of the lanes, a part of the inner edge of the both lanes 1, 1a has a serration 1d. A pair of spaced and parallel upright side plates 2 and 2 extend upwardly and longitudinally of the attachment plate 1 in positions inwardly spaced from the opposite side edges of the attachment plate covering the distance between the opposite ends of the attachment plate. Said side plates are held in position to face each other against the attachment plate so they wont move, but are adjustable in the axial direction of the attachment plate. For adjustment of the side plates 2, each of the side plates is provided at its lower end with a horizontally and outwardly extending toothed flange 2a, 2a and the attachment plate is provided with a pair of horizontally and inwardly extending flanges on the opposite sides having teeth which mesh with the teeth on the flanges of the side plates. Each of the side plates 2 is preferably provided with a longitudinal inclined portion 2b sunstantially in the center thereof which connects an upper portion 2d and lower portion 2c of the plate. The distance between the upper portions of the opposite side plates is shorter than the distance between the lower portions. In the lower portion of each side plate, a hole 4 is provided and a transverse shaft 5 extends through the holes 4 in the side plates 2 and is fixedly held therein. The front edge of the side plate 2 has cam face including substantially vertical component 25 in the axial direction of the ski. The upper edge of the side plate preferably comprises an arcuate component 26 centering the center of the hole 4. Mounted on the shaft 5 are a pair of ski boot heel holding or guide members 6, a stepping-down member 7, a release lever 8 and a vertical rod 9. The holding member 6 comprises a pair of side wall members the head portions of which form a heel receiving portions 6a, extending and flaring forwardly toward a toe holding device at the fore end of the ski (not shown) and rear portion of which forms a parallel portion 6b, and a connecting member 60 connecting the two wall members. The parallel portions 6b, 6b are provided with slots 6d, 6d and the shaft 5 extends through the slots. The holding member 6 arranged on the innerside of the lower portion 20 of the side plate 2 functions as guides so as to hug the ski boot heel and properly positions the heel with respect to the ski and also as means for firmly holding the ski boot on the ski. The connecting member 60 is provided with a slot 6e substantially in the center thereof. Both side edges of the slot have serrations 6f which mesh with fixed teeth 3a of a plate 3 mounted on the attachment plate 1 and if necessary the position of the holding members can be adjusted in the longitudinal direction of the ski by means of changing the position of serrations 6 f engaging to the fixed teeth 3a and escaping the shaft 5 along the slots 6d, 611 as well as conventional manner. The holding members 6 are mounted on the transverse shaft 5. This member 6 works to help the operation of a holding-down member 17 referring hereinafter, and this holding member 6 is not necessarily needed in this invention. The steppingdown member 7 has a smoothly curved fore portion 11 which extends between the holding members 6, and a straight flat portion 12 positioned below the lower end of a vertically extending spring case and having a hole 12c as large as the size of the rod 9, and side walls 12a, 12a (see FIGS. 4 and 6). Each of side walls 12a is provided with a hole 12b and the stepping-down member 7 receives the shaft 5 through said holes 12b, 12b at the inner side of the parallel portions 6b, 6b of the holding member 6. The release lever 8 comprises preferably a pair of plate arm 8a, 80, upper end of the arms are connected as a unit by a bridge presenting a pushing-down pressure receiving portion 13 which is dis posed outside the spring case 10 to be pushed down by a skiers pole, for example and lower ends of the arms 8a have cam portions 14, 14 positioned below the lower end of the spring case 10 so as to contact it at a front portion of the center of the bottom hole 10a 2. holes 8b, 8b receiving the shaft 5. Said cam portions 14, 14 include circle segment centering the fore and lower portion of the center of the hole 8b. Thus, when the pressure receiving portion 13 is pushed down by the skiers pole, the cam portion 14 is pivoted about the shaft 5 to push the spring case 10 upwardly in a manner to be described hereinbelow. Preferably the release lever 8 is as usual provided with a spring 27 at a proper portion of the lever so as to bias the lever to the predetermined position of the spring case 10. The vertical rod 9 serves as a guide for a coiled compression spring 15 received in the spring case 10 surrounding the rod and its lower end extends through the bottom of the spring case 10 and the hole 120 of the member 7, and terminates at an annular portion where the vertical rod 9 is pivoted on the transverse shaft 5 and the threaded upper end on which a spring force adjusting screw 16 is threaded. Thus, it will be appreciated that with the spring 15 in abutment at the upper end against the adjusting screw and in abutment at the lower end against the floor of the spring case, when the adjusting screw is turned in either direction, the force of the spring can be adjusted as desired. The top of the spring case 10 is open for receiving the adjusting screw 16 whereas the bottom 10b of the case is substantially closed having an opening 10a just sufficient to allow the vertical shaft 9 to extend therethrough. The spring case 10 has a projection 18 which extends substantially horizontally and forwardly of the case at an intermediate position between the upper and lower ends thereof and has a transverse opening 18 for receiving the head of an adjusting screw 19 the function of which will be described immediately below. A ski boot heel holding-down member 17 is adjustably mounted on the projection 18 by means of the adjusting screw 19 and for the purpose, the holding-down member has a threaded opening 21 in a portion positioned below the projection 18 in alignment with the opening 18' which threadably receives the threaded shank of the adjusting screw 19. Thus, when the adjusting screw 19 is turned in either direction, the height of the holding-down member 17 can be adjusted with respect to the spring case 10 as desired. The lower end of the adjusting screw 19 extends down through the threaded opening 21 in the holding-down member 17 into a threaded opening (not shown) in a horizontal screw receiving plate 20 which is firmly secured to the floor of the spring case 10. The adjustment of the position of the holding-down member 17 with respect to the spring case 10 can be effected by turning the screw 19 at the head thereof using any conventional screw driver as conventionally practiced.

The spring case 10 also has a transverse opening 22 in and adjacent to the projection 18 having the axis at right angles to the axis of the spring case 10 and a shaft 23 extends through the opening 22. The opposite ends of the shaft 23 rotatably carry rollers 24 which normally ride on the substantially vertical face portion at the front edge of each of the side plates 2 when the holding device is in its ski boot heel holding position (FIGS. 2 and 4).

In use, the skier first pushes down the release lever 8 at the upper end pressure receiving portion 8 by means of his pole, finger or any other suitable means (assuming that the holding device is in the position as shown in FIGS. 2 and 4) to cause the release lever to pivot at its lower cam portion in the clockwise direction as seen in FIGS. 2, 3 and 4 about the transverse shaft 5 toward the position as shown in FIG. 3. As the release lever 8 pivots in the manner mentioned above, the cam portion 14 of the release lever pushes upwardly on the floor of spring case 10 to cause the case to pivot in the clockwise direction about the transverse shaft 5. It is because when the lever 8 pivots about the shaft 5, the cam 14 having the center axis thereof at the fore-down portion of the center of the hole 8b receiving the shaft 5 contacts the bottom 10b of the case 10 at the fore portion of the axis in the bottom 10b, to which axis it is assumed that the spring 15 works, and provides a torque to rotate the case clockwise. As the spring case 10 pivots in the manner mentioned above, the rollers 24 carried on the transverse shaft 23 which is supported in the spring case roll upwardly along the vertical front edge vertical faces 25 of the side plates 2. As the release lever 8 continues to pivot in the clockwise direction about the transverse shaft 5, the rollers 24 reach the upper limit of the vertical face portions 25 of the side plates 2. Thereafter, as the release lever 8 further continues to pivot in the clockwise direction, spring case 10 moves in a clockwise direction because the pivoting cam portion 14 engages the floor of spring case 10 at a point on the left-hand side of the axis of the spring case whereby the rollers 24 move from the vertical face portions 25 onto the arcuate upper face portions 26 of the side plates 2. As the spring case pivots in the clockwise direction in the manner mentioned above, the ski-boot heel holding-down member 17 integrally connected to the case 10 and the stepping-down member 7 pivot in the clockwise direction. However, when the skier desires to place the skis in a ski bag, the heel holding-down member 17 and stepping-down member 7 are pivoted further in the clockwise direction beyond the position in which these members provide a clearance just sufficient to receive the heel of a ski boot therebetween and the rollers 24 are also forced to roll backwardly along the upper faces 26 of the side plates 2 so that the holding device may not hinder placing the skis in the ski bag.

After the heel holding device has been pivoted to the heel release or receiving position (see FIG. 3), when the skier steps into the heel holding device he presses the stepping-down member 7 down with his ski boot heel, and the ski boot heel is readily properly positioned in the holding device with respect to the ski, whereby the skier is ready for skiing. To describe in more detail, when the skier steps into the heel holding device the curved front arcuate portion 11 of the stepping-down member 7 is in the heel release or receiving position as shown in FIG. 3; the stepping-down member is caused to pivot in the counterclockwise direction about the transverse shaft which in turn causes the vertical rod 9 which threadably extends through the rear straight portion 12 of the stepping-down member 7 to pivot in the counterclockwise direction about the transverse shaft 5 resulting in pivotal movement of the spring case 10 in the counterclockwise direction about the transverse shaft 5. The operation of the ski boot heel holding device of the invention for receiving the heel will now be described in further detail. When the skier steps the front arcuate portion 11 of the steppingdown member 7 by his ski boot heel, the stepping-down member pivots in the counterclockwise direction about the transverse shaft 5 As mentioned above, when the holding device is in its release position, the rollers 24 carried on the spring case 10 ride on the arcuate upper faces 26 of the side walls 2 and accordingly, in the release position of the holding device the spring case 10 is in a position higher than when the holding device is in its ski boot heel holding position (FIGS. 2 and 4). The difference in position corresponds substantially to the length of one of the vertical surface portions 25 of the side plates 2 and the coiled spring 15 is compressed by a degree substantially corresponding to the distance by which the spring case 10 has moved upwardly. On the other hand, since the vertical shaft 9 a substantial portion of which is surrounded by the spring 15 within the spring case 10 is in threaded engagement at the upper end with the spring force adjusting screw 16 and the lower end of the rod 9 extends through the floor of the spring case and the straight flat portion 12 of the stepping-down member 7 and is pivoted on the transverse shaft 5, as the spring case 10 pivotally slides on the arcuate portions 26 with the rollers 24 the vertical rod 9 and stepping-down member 7 follow the sliding movement of the spring case. Similarly, as the steppingdown member 7 pivots about the transverse shaft 5, the spring case 10 pivots about the transverse shaft 5 following the pivotal movement of the stepping-down member. With the ski boot heel holding device of the invention in the heel releasing or receiving position (FIG. 3), when the skier steps down the curved front portion 11 of the stepping-down member 7, the ski boot heel is guided along the two holding members 6a until the heel is properly positioned with respect to the ski by being hugged by the holding members 6. Immediately after the ski boot heel has been properly positioned in the holding device by the holding members 6, the rollers 24 which are now on the upper arcuate faces 26 snappingly and momentarily roll down onto the vertical face portions of the side plates 2. Following up the snapping rolling-down movement of the rollers 24,

the heel holding-down member 17 quickly descends to abut against the upper edge of the ski boot heel thereby to firmly hold the heel against the ski down. Thus, the retaining force of the holding members 6 on the heel is assisted by the holding-down force of the heel holdingdown member 17. Since the ski boot heel holding mechanism mentioned above is held in its resiliently heel holding position by the vertical resilient force provided by the spring 15, even if the skiers leg is subjected to any stress which tends to displace the ski boot from the proper position while skiing, the spring absorbs such stress thereby preventing the stress from affecting the toe holding device (not shown). Although the ski boot heel is resiliently held by the vertical force provided by the spring 15 in the illustrated preferred embodiment, if necessary or desired, the configuration of the front edge including the vertical face portion 25 of each of the side plates 2 may be varied so that the ski boot heel may be more easily pushed against the holding device.

As clear from the foregoing, according to the present invention, the ski boot heel is resiliently and firmly held in position by only the vertical force from the spring and accordingly, even if the skiers leg is subjected to stress sufficient to displace the ski boot heel properly held in position with respect to the ski while skiing, the toe holding device (not shown) can smoothly return the heel to the proper holding position in the heel holding device because the heel holding device has no component which impedes the heel returning action of the toe holding device. And even if the ski boot heel held in the heel holding device moves vertically and upwardly against the vertical downward force of the spring, since the heel holding-down member 7 moves vertically and upwardly in a linear path together with the rollers 24 which then roll along the front edge vertical face portions 25 of the side plates 2 as distinguished from the arrangement of the corresponding heel holding-down member in a conventional ski boot heel holding device in which the heel holding-down member moves in an arcuate path. Thus, according to the present invention, the engagement between the heel and heel holding down member will not be readily broken off. Furthermore, according to the present invention, the heel holding mechanism is so arranged that if the ski boot heel held in the heel holding device moves vertically and upwardly by an amount over a predetermined amount, since the heel holding-down member moves upwardly beyond the vertical face portions 25 of the side plates 2, in the same manner as when the release lever is operated, the rollers 24 roll beyond the top of the vertical face portions 25 of the side plates 2 onto the upper arcuate face portions 26 of the side plates whereupon the ski boot heel is disengaged from the holding-down member.

Thus, since the ski boot heel holding device of the invention is so designed that the ski boot heel is resiliently held in position by only the direct vertically applied force of the resilient element, the heel holding device has no element which produces a forwardly directed force acting on the toe holding device whereby the elasticity of the entire safety binding of which the heel holding device of the invention and the toe holding device are constituent elements can be increased. In addition, the ski boot heel can be firmly and resiliently held in position by the heel holding or guide members 6, and heel holding-down members 7 and the directly applied vertical force of the spring 15. Thus, the invention provides an improved ski boot heel holding device which can effectively achieve the above-mentioned various objects of the invention.

In the foregoing, the invention has been described with reference to a specific illustrative embodiment. It will be evident, however, that variations and modifications, as well as the substitution of equivalent parts or elements for those shown therein for illustrative, may be made without departing from the broader scope and spirit of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense. What is claimed is:

1. A heel holding device for safety ski bindings comprising in combination a ski, an attachment plate secured to said ski on the upper surface of the latter, a pair of parallel and spaced side plates mounted on said attachment plate for adjustment axially of said ski each having guide face portions which are normally vertical and normally parallel with respect to the plane of said ski, respectively, a transverse shaft extending between said side plates and fixedly secured to the side plates, a pair of ski boot heel guide members fixedly secured at one end to said transverse shaft and flaring at the other end, a pivotal spring case enclosing a vertical rod having a threaded upper end and the lower end extending through the floor wall of said spring case and terminating in an annular portion which is pivoted on said transverse shaft and a coiled spring surrounding said vertical rod within said case for normally urging the spring case downwardly toward said ski, an adjusting screw threaded on said threaded upper end of the vertical rod to permit the force of said spring to be adjusted, said spring case further having a bored projection extending substantially horizontally and forwardly of the spring case in a position between the upper and lower ends of the case, said projection having a transverse opening hole and a vertical opening, a pivotal lever having a downward force receiving portion at the upper end and a cam portion at the lower end which is pivoted on said transverse shaft, a bored heel holdingdown member mounted .on said projection for engaging the heel of a ski boot and adjustable with respect to the projection and having a vertical threaded opening in alignment with said vertical opening in the projection, a second adjusting screw extending through said vertical opening in the projection and said threaded opening in the heel holding-down member to permit the height of the holding-down member to be adjusted with respect to said spring case, a second transverse shaft extending through said transverse opening in the projection and carrying rollers at the opposite ends, said rollers normally riding on said substantially vertical guide face portions of the side plates, and a stepping-down member having a curved front portion for holding said heel of the ski boot thereon and a straight portion having an opening for snugly receiving said lower end of the vertical rod so as to pivotally move together with said spring case.

2. A heel holding device for safety ski bindings, comprising:

a substantially horizontally positioned attachment plate adapted to be secured on a ski having a longitudinal axis in the horizontal plane;

a pair of spaced and substantially parallel upright side plates fastened to the attachment plate, each of said plates having a vertical guide element positioned substantially at a right angle to the ski axis at the fore edge and an arcuate guide element at the upper edge;

hollow spring case movably mounted on a vertical surface with respect to the ski axis between said side plates, said spring case having an open upper end and a porous lower end and having a heel holding-down member mounted thereon, a roller mounted on the lateral outside of said spring case, said roller being movable along said guide elements, a vertical rod movably received in said spring case, and a spring biasing the spring case on the inner side of the hollow spring case; stepping-down member arranged under the spring case and located substantially in the center portion of the lower end of the spring case for holding the heel of a ski boot, said stpping-down member comprising a fore portion, a side wall portion and a flat portion;

release lever comprising a pair of plate-like arms,

the lower ends of which having a cam surface located on each side of said stepping-down member under the spring case, the upper ends of which being connected with a downward force receiving portion; and a transverse shaft extending across the ski axis direction through the lower portion of the vertical rod, the side wall portion of the release lever and the side plates; and characterized in that said spring being positioned between the lower end of the spring case and a cap mounted on the upper end of the vertical rod and adapted to be moved freely within the hollow wall of thespring case, said vertical rod passing through a hole provided on the lower end of said spring case and a hole provided on the flat portion of said stepping-down member for receiving the transverse shaft, a portion of the cam surface of the release lever being a curved segment centered at the fore-down portion of the center of the hole receiving the transverse shaft, a clockwise rotation of the lever around the shaft operating the case following the edge of the respective side plate, whereby when the roller is contacting the vertical element of the side plate, the spring case moves vertically, and while the roller is contacting the arcuate element, the spring case moves circularly, and the steppingdown member being inoperative while the case is moving vertically, said stepping-down member moving circularly when said case is in circular motion. 3. The heel holding device according to claim 2, wherein said arcuate element of the side plate is a part of a circle centered at the center of the hole receiving the transverse shaft. 

1. A heel holding device for safety ski bindings comprising in combination a ski, an attachment plate secured to said ski on the upper surface of the latter, a pair of parallel and spaced side plates mounted on said attachment plate for adjustment axially of said ski each having guide face portions which are normally vertical and normally parallel with respect to the plane of said ski, respectively, a transverse shaft extending between said side plates and fixedly secured to the side plates, a pair of ski boot heel guide members fixedly secured at one end to said transverse shaft and flaring at the other end, a pivotal spring case enclosing a vertical rod having a threaded upper end and the lower end extending through the floor wall of said spring case and terminating in an annular portion which is pivoted on said transverse shaft and a coiled spring surrounding said vertical rod within said case for normally urging the spring case downwardly toward said ski, an adjusting screw threaded on said threaded upper end of the vertical rod to permit the force of said spring to be adjusted, said spring case further having a bored projection extending substantially horizontally and forwardly of the spring case in a position between the upper and lower ends of the case, said projection having a transverse opening hole and a vertical opening, a pivotal lever having a downward force receiving portion at the upper end and a cam portion at the lower end which is pivoted on said transverse shaft, a bored heel holding-down member mounted on said projection for engaging the heel of a ski boot and adjustable with respect to the projection and having a vertical threaded opening in alignment with said vertical opening in the projection, a second adjusting screw extending through said vertical opening in the projection and said threaded opening in the heel holding-down member to permit the height of the holdingdown member to be adjusted with respEct to said spring case, a second transverse shaft extending through said transverse opening in the projection and carrying rollers at the opposite ends, said rollers normally riding on said substantially vertical guide face portions of the side plates, and a stepping-down member having a curved front portion for holding said heel of the ski boot thereon and a straight portion having an opening for snugly receiving said lower end of the vertical rod so as to pivotally move together with said spring case.
 2. A heel holding device for safety ski bindings, comprising: a substantially horizontally positioned attachment plate adapted to be secured on a ski having a longitudinal axis in the horizontal plane; a pair of spaced and substantially parallel upright side plates fastened to the attachment plate, each of said plates having a vertical guide element positioned substantially at a right angle to the ski axis at the fore edge and an arcuate guide element at the upper edge; a hollow spring case movably mounted on a vertical surface with respect to the ski axis between said side plates, said spring case having an open upper end and a porous lower end and having a heel holding-down member mounted thereon, a roller mounted on the lateral outside of said spring case, said roller being movable along said guide elements, a vertical rod movably received in said spring case, and a spring biasing the spring case on the inner side of the hollow spring case; a stepping-down member arranged under the spring case and located substantially in the center portion of the lower end of the spring case for holding the heel of a ski boot, said stpping-down member comprising a fore portion, a side wall portion and a flat portion; a release lever comprising a pair of plate-like arms, the lower ends of which having a cam surface located on each side of said stepping-down member under the spring case, the upper ends of which being connected with a downward force receiving portion; and a transverse shaft extending across the ski axis direction through the lower portion of the vertical rod, the side wall portion of the release lever and the side plates; and characterized in that said spring being positioned between the lower end of the spring case and a cap mounted on the upper end of the vertical rod and adapted to be moved freely within the hollow wall of the spring case, said vertical rod passing through a hole provided on the lower end of said spring case and a hole provided on the flat portion of said stepping-down member for receiving the transverse shaft, a portion of the cam surface of the release lever being a curved segment centered at the fore-down portion of the center of the hole receiving the transverse shaft, a clockwise rotation of the lever around the shaft operating the case following the edge of the respective side plate, whereby when the roller is contacting the vertical element of the side plate, the spring case moves vertically, and while the roller is contacting the arcuate element, the spring case moves circularly, and the stepping-down member being inoperative while the case is moving vertically, said stepping-down member moving circularly when said case is in circular motion.
 3. The heel holding device according to claim 2, wherein said arcuate element of the side plate is a part of a circle centered at the center of the hole receiving the transverse shaft. 